I did a presentation, on 9th of October 2020, at the Hacktivity 2020 OnLine – IT Security Festival about “Hacking the Hacktivity 2019 Badge: How To Brick The Device And Resurrect it With Another Soul”.
Here you can find:

• The presentation in PDF format
• The Hacktivity 2019 badge, SAMD21 co-processor firmware, this include also the pinout and other documentation
• An Arduino sample sketch that includes examples about how to use the display and interact with on board peripherals like LEDs, touch buttons, buzzer
• The Official Hactivity 2019 Badge documentation
• The Original Disobey 2019 badge SAMD21 firmware, the above firmware has been forked from this repository and then modified
• The Original Disobey 2019 firmware and documentation
• The Atmel SAMD21 family Data Sheet
• Espressif ESP32-WROOM-32 Data Sheet
• TTL Serial Adapter (affiliate link)
• Segger J-Link Edu Mini (affiliate link)
• FT2232H based break-out board (affiliate link)